A well-executed study generates data from which clinical inferences will ultimately be drawn. The proper management of data and appropriate analytic techniques are essential components of the overall study to ensure that valid inferences will be made. The goals of the HRCA/Harvard Reasearch Nursing Home Data Management and Analysis Core are to provide leadership in all phases of data management and analyses encompassing study planning and design, implementation, data analysis and the preparation of manuscripts for all studies within the project. The primary responsibilities of the Core will be to provide expertise in the areas of data management, database programming, study design and sampling, and statistical analyses. Specific aims of the Core are as follows: 1. To assemble and manage a database of longitudinal information obtained from the subjects during screening and during the conduct of individual projects 2. To collaborate with the Epidemiology Core and the survey consultant in all phases of study design including determining the sampling scheme for the study, determining the weighting adjustments for unequal probability selection of observations, and accounting for the clustering of observations, stratification, and nonresponse. 3. To provide methodological and analytic expertise to project investigators including study design, conduct, data analysis, interpretation and manuscript preparation. To achieve these goals, the members of the Core will have ongoing collaboration in all aspects of the planning and evaluation of each of the proposed projects. The Core will also have continuous interaction with core staff to ensure the consistency and efficiency of procedures. The Core is a resource that has appropriate state-of-the-art software and expertise in data collection procedures that will enable the management and analysis of the data that result from these projects.